unix: unify memory functions on BSD

Make Madvice, Mlock, Mlockall, Mprotect, Msync, Munlock and Munlockall
available equally on all BSD flavors. NetBSD was previously lacking
SYS_MSYNC, so add it.

Reorder the //sys function prototype alphabetically and clean up already
implemented syscalls everywhere.

Also add tests for Mprotect, Msync and Madvice - now that they're
available on all unix platforms.

Fixes golang/go#18513

Change-Id: I0eb502d72c7e991f191fb96225ef04e8297d8b8d
Reviewed-on: https://go-review.googlesource.com/56172
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
diff --git a/unix/zsyscall_openbsd_arm.go b/unix/zsyscall_openbsd_arm.go
index ca2ed7d..41572c2 100644
--- a/unix/zsyscall_openbsd_arm.go
+++ b/unix/zsyscall_openbsd_arm.go
@@ -266,6 +266,106 @@
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
+func Madvise(b []byte, behav int) (err error) {
+	var _p0 unsafe.Pointer
+	if len(b) > 0 {
+		_p0 = unsafe.Pointer(&b[0])
+	} else {
+		_p0 = unsafe.Pointer(&_zero)
+	}
+	_, _, e1 := Syscall(SYS_MADVISE, uintptr(_p0), uintptr(len(b)), uintptr(behav))
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func Mlock(b []byte) (err error) {
+	var _p0 unsafe.Pointer
+	if len(b) > 0 {
+		_p0 = unsafe.Pointer(&b[0])
+	} else {
+		_p0 = unsafe.Pointer(&_zero)
+	}
+	_, _, e1 := Syscall(SYS_MLOCK, uintptr(_p0), uintptr(len(b)), 0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func Mlockall(flags int) (err error) {
+	_, _, e1 := Syscall(SYS_MLOCKALL, uintptr(flags), 0, 0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func Mprotect(b []byte, prot int) (err error) {
+	var _p0 unsafe.Pointer
+	if len(b) > 0 {
+		_p0 = unsafe.Pointer(&b[0])
+	} else {
+		_p0 = unsafe.Pointer(&_zero)
+	}
+	_, _, e1 := Syscall(SYS_MPROTECT, uintptr(_p0), uintptr(len(b)), uintptr(prot))
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func Msync(b []byte, flags int) (err error) {
+	var _p0 unsafe.Pointer
+	if len(b) > 0 {
+		_p0 = unsafe.Pointer(&b[0])
+	} else {
+		_p0 = unsafe.Pointer(&_zero)
+	}
+	_, _, e1 := Syscall(SYS_MSYNC, uintptr(_p0), uintptr(len(b)), uintptr(flags))
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func Munlock(b []byte) (err error) {
+	var _p0 unsafe.Pointer
+	if len(b) > 0 {
+		_p0 = unsafe.Pointer(&b[0])
+	} else {
+		_p0 = unsafe.Pointer(&_zero)
+	}
+	_, _, e1 := Syscall(SYS_MUNLOCK, uintptr(_p0), uintptr(len(b)), 0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func Munlockall() (err error) {
+	_, _, e1 := Syscall(SYS_MUNLOCKALL, 0, 0, 0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
 func pipe(p *[2]_C_int) (err error) {
 	_, _, e1 := RawSyscall(SYS_PIPE, uintptr(unsafe.Pointer(p)), 0, 0)
 	if e1 != 0 {
@@ -785,74 +885,6 @@
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Mlock(b []byte) (err error) {
-	var _p0 unsafe.Pointer
-	if len(b) > 0 {
-		_p0 = unsafe.Pointer(&b[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
-	}
-	_, _, e1 := Syscall(SYS_MLOCK, uintptr(_p0), uintptr(len(b)), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Mlockall(flags int) (err error) {
-	_, _, e1 := Syscall(SYS_MLOCKALL, uintptr(flags), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Mprotect(b []byte, prot int) (err error) {
-	var _p0 unsafe.Pointer
-	if len(b) > 0 {
-		_p0 = unsafe.Pointer(&b[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
-	}
-	_, _, e1 := Syscall(SYS_MPROTECT, uintptr(_p0), uintptr(len(b)), uintptr(prot))
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Munlock(b []byte) (err error) {
-	var _p0 unsafe.Pointer
-	if len(b) > 0 {
-		_p0 = unsafe.Pointer(&b[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
-	}
-	_, _, e1 := Syscall(SYS_MUNLOCK, uintptr(_p0), uintptr(len(b)), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Munlockall() (err error) {
-	_, _, e1 := Syscall(SYS_MUNLOCKALL, 0, 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Nanosleep(time *Timespec, leftover *Timespec) (err error) {
 	_, _, e1 := Syscall(SYS_NANOSLEEP, uintptr(unsafe.Pointer(time)), uintptr(unsafe.Pointer(leftover)), 0)
 	if e1 != 0 {